Itchy, flaky scalps are a common symptom of dandruff and seborrheic dermatitis. Fortunately, there are many products available over the counter (OTC) to reduce and sometimes eliminate dandruff. Shampoos specifically designed to treat dandruff are one of the most widely used anti-dandruff treatments. Learn about the basic and active ingredients found in most OTC anti-dandruff shampoos.
Causes of Dandruff
A common misconception about dandruff is that dry skin is the root cause of this condition. Dry skin rarely produces flakes that are visible to the naked eye. Dandruff can be the result of an excessively oily scalp or a yeast infection of the scalp. An oily scalp can be freed from dandruff with regular shampooing by massaging the shampoo into the scalp for five minutes and thoroughly rinsing the shampoo out. The scalp massage loosens the dead skin cells while the shampoo removes excess oil. Both the shampoo and dead skin are washed away when the hair is rinsed. However, for dandruff caused by yeast or seborrheic dermatitis, anti-dandruff shampoos are needed to fight the fungal infection and dissolve the dead skin. Before treating any scalp condition, consult a doctor to rule out any underlying health causes for your dandruff.
Basic Shampoo Ingredients
Most OTC shampoos contain water, a detergent (cleaning agent), surfactant (lather making agent), salt, fragrance (natural and artificial), preservative and food coloring. With the exception of water and salt (sodium chloride), different chemical compounds are used depending on the desired result of the shampoo. For example, when it comes to choosing a surfactant, one shampoo may use sodium laureth sulfate while another may use potassium or ammonium laureth sulfate--it depends on the manufacturer’s formula. Many shampoos also contain vitamins and moisturizing alcohols to prevent too much of the hair and scalp's natural oils from being stripped away during cleansing. In the case of anti-dandruff shampoos, another ingredient, which may be listed on the product as the active ingredient, is used to help control dandruff.
Coal tar is the active ingredient in Neutrogena's T-Gel Shampoo. This ingredient is used to treat many scalp conditions that involve dandruff and other thick crust conditions such as eczema and psoriasis. The Mayo Clinic recommends massaging a shampoo with coal tar into the scalp and leaving it there for five minutes. It is advised to rinse the hair and scalp thoroughly after use. Limit your sun exposure after using a shampoo containing this ingredient because the treated area will be sensitive to direct sunlight or sunlamps and it can increase your risk of getting skin cancer.
Salicylic Acid and Sulfur
Salicylic acid and sulfur are used in combination to treat many skin disorders including dandruff. Sebex uses this combination in its anti-dandruff shampoo. The two ingredients work together to provide temporary control of scaling and itching as a result of psoriasis, dandruff and seborrheic dermatitis. Salicylic acid works to break down the dead skin cells to reveal the new skin underneath. It also aids in the penetration of antifungal agents. Salicylic acid also is a mild antiseptic that may heal any irritation to the scalp from scratching. Sulfur is an antifungal ingredient that gets rid of the yeast (fungus) that causes dandruff in some people.
This ingredient is found in Nizoral shampoo. Ketoconazole is a fungicide and is used in shampoos to treat dandruff that develops because of a yeast infection of the scalp. Shampoos containing this ingredient are most often prescribed for serious fungal infections. A shampoo containing 2 percent ketoconazole can help control moderate dandruff. The shampoo must be massaged into the scalp and left on for at least five minutes so the ketoconazole can work at removing the infection. Consult a doctor before using a shampoo containing ketoconazole as the ingredient may cause liver damage.
The Selsun Blue line of dandruff shampoos uses selenium sulfide as its active ingredient. OTC shampoos contain 1 percent selenium sulfide while 2 1/2 percent is available by prescription only. Selenium sulfide works to get rid of the yeast that causes dandruff. The Mayo Clinic recommends only using this ingredient twice a week by applying one or two teaspoons of the shampoo on the scalp, massaging it in and leaving on for no more than three minutes. If your hair has been chemically treated or if you have light-colored hair, the product may discolor the hair if not rinsed out completely.
Head & Shoulders is a popular OTC shampoo that uses zinc pyrithione as its active ingredient. Zinc pyrithione is an antifungal ingredient that also works to break down the dead skin cells and treat any fungus that may be the underlying cause of the dandruff. Unlike many of the other anti-dandruff ingredients, zinc pyrithione is gentle enough for everyday use. For the ingredient to remain effective, it is recommended that it be used at least twice a week. Shampoos containing this ingredient are massaged into the scalp and left on for several minutes before rinsing. Once the dandruff is under control, treatment can be downgraded to once a week.